Selective call receivers generally operate using batteries to allow the selective call receivers to be portable and compact. The selective call receivers must, therefore, utilize power saving techniques such as switching the receiver circuit of the selective call receiver `on` and `off` in order to obtain the maximum possible life from the batteries. The `on` time interval of the receiver circuit when the selective call receiver may potentially receive a selective call message addressed to the selective call receiver consumes power. Conversely, the `off` interval inhibits reception of the signal by the receiver circuit, thereby conserving power. Thus, it is desirable to minimize the `on` time interval of the receiver circuit.
When the receiver circuit looses the system signal either from the selective call receiver being out of range of the system transmitters, from being shielded by buildings, or when the channel is shared with another signal protocol, the receiver circuit typically returns to the initial synchronization acquisition mode. Regrettably, the synchronous acquisition mode is not very efficient in terms of battery life. Thus, a selective call receiver which is in a weak signal condition for a long period of time will consume a great deal of battery power to re-synchronize. Also when selective call receivers are turned `off` and then `on` by the user, the receiver circuit usually powers up in the synchronization acquisition mode to search for the system signal, wasting much battery power.
Thus, what is needed is a selective call receiver which conserves battery power by limiting the time which the selective call receiver operates in the power consuming synchronization acquisition mode.